Feeding a high fat, low carbohydrate diet resulted in adaptive decreases in: activation of hormone sensitive lipase in adipocytes, decreased insulin binding in adipocytes and purified liver membranes, decreased glucose transport in adipocytes and decreased lectin binding by purified liver membranes. Significant changes were shown in the carbohydrate composition of glycoproteins as well as in the phospholipid pattern of purified liver membranes as a result of fat feeding. Studies on the possible role of precursor pool sizes of nucleotide sugars, sugar transferase enzymes and the dolichol phosphate system in these changes are in progress.